Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First Direct “Chemical Fingerprint” of an Exoplanet orbiting a Sun-Like Star

13.01.2010
Astronomers have obtained the first direct spectrum – a “chemical fingerprint” – of a planet orbiting a distant, Sun-like star, providing direct data about the composition of the planet's atmosphere.

Such “chemical fingerprinting” is a key technique in the search for habitable planets around other stars. As such, the result represents a milestone in the search for life elsewhere in the Universe. More directly, results like this are expected to provide new insight into how planets form.


Image of the HR 8799 system. In the center, the host star HR 8799. Further investigation shows that three of the specks surrounding the star are planets (marked): Starting at 11 o\'clock, clockwise: HR 8799b, HR8799c and HR8799d. The other specks and patterns are artefacts, which are unavoidable in a challenging observation like this one – star and planets are extremely close, and the star is a few thousand times brighter than the planets. The distance from the star to HR 8799c corresponds to 38 times the average Earth-Sun distance. Image credit: MPIA / W. Brandner

The search for life on other planets is one of the most exciting endeavours of modern astronomy. Over the past decade, astronomers have discovered more than 400 exoplanets (that is, planets orbiting stars other than the Sun). In order to judge a planet's habitability, or even detect tell-tale traces of habitation, astronomers need to do more than just detect such planets: They need to find out what the planet – more specifically, its atmosphere – is made of. To this end, they need to obtain the planet's spectrum, a “chemical fingerprint” that can be measured by examining the light received from the planet. Now astronomers have, for the first time, measured the spectrum of an exoplanet orbiting a Sun-like star directly – an important step in the ongoing search.

The research team, which includes three researchers from the Max Planck Institute for Astronomy (MPIA) and two from Canadian universities, studied the planetary system around the bright, very young star HR 8799, 130 light-years from Earth, located within the constellation Pegasus. The planetary system resembles a scaled-up version of our own Solar System and includes three giant planets, which had been detected in 2008 in another study. “Our target was the middle planet of the three, which is roughly ten times more massive than Jupiter and has a temperature of about 800 degrees Celsius,” says team member Carolina Bergfors (MPIA), who participated in the observations as part of her PhD work. The researchers recorded the spectrum using the NACO instrument installed at the European Southern Observatory's Very Large Telescope (VLT) in Chile, in particular its combined camera/spectrograph CONICA, which was developed at the MPIA and at the Max Planck Institute for Extraterrestrial Physics.

As the host star is several thousand times brighter than the planet, and the two are very close, obtaining such a spectrum is an immense feat. Markus Janson of the University of Toronto, lead author of the paper reporting the new findings, explains: “It's like trying to see what a candle is made of, by observing it next to a blinding 300 Watt lamp – from a distance of 2 kilometres [1.3 miles].” Carolina Bergfors (MPIA), whose work on this project is part of her PhD studies, adds: “It took more than five hours of exposure time, but we were able to tease out the planet's spectrum from the host star's much brighter light.”

In time, the astronomers hope that this technique will help them gain a better understanding of how planets form. As a likely first step, they aim to record the spectra of the two other giant planets orbiting HR 8799 – which would represent the first time that astronomers would be able to compare the spectra of three exoplanets that form part of one and the same system. As a much more distant goal, the technique will allow astronomers to examine exoplanets for habitability, or even signs of life.

More immediately, the results pose something of a challenge to current models of the exoplanet's atmosphere. “The features observed in the spectrum are not compatible with current theoretical models,” explains MPIA's Wolfgang Brandner, a co-author of the study. “We need to take into account a more detailed description of the atmospheric dust clouds, or accept that the atmosphere has a different chemical composition than previously assumed.”

Contact information

Dr. Wolfgang Brandner (Coauthor)
Max Planck Institute for Astronomy, Heidelberg, Germany
Phone: (0|+49) 6221 – 528 289
E-mail: brandner@mpia.de
Dr. Markus Pössel (PR)
Max Planck Institute for Astronomy, Heidelberg, Germany
Phone: (0|+49) 6221 – 528 261
E-mail: poessel@mpia.de
Background Information
The results described here have been published as M. Janson et al., "Spatially resolved spectroscopy of the exoplanet HR 8799 c", Letter to Astrophysical Journal.

The team is composed of M. Janson (University of Toronto, Canada), C. Bergfors, M. Goto, W. Brandner (Max-Planck-Institute for Astronomy), and D. Lafrenière (University of Montreal, Canada).

Dr. Markus Pössel | Max-Planck-Institut
Further information:
http://www.mpia.de
http://www.mpia.de/Public/menu_q2.php?Aktuelles/PR/2010/PR100112/PR_100112_en.html

More articles from Physics and Astronomy:

nachricht Heating quantum matter: A novel view on topology
22.08.2017 | Université libre de Bruxelles

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>